Properties and efficiency of catalysts produced by an ION beam processing technology

Paper presents the test results and properties of catalysts produced by an ion implantation technique. New catalysts showed the same efficiency with much lower expense of noble metals as compared with the catalysts produce by an impregnation. Also shown, that the ion bombardment did not reduce the specific surface area of the catalyst.Приведены свойства и результаты испытаний катализаторов, полученных путем ионной имплантации. По сравнению с катализаторами, полученными обычными технологиями, опытные катализаторы показывают те же значения коэффициента нейтрализации при значительно меньшем содержании благородных металлов. Показано, что ионная бомбардировка не уменьшает эффективную поверхность носителей

The structure of Green functions in quantum field theory with a general state

In quantum field theory, the Green function is usually calculated as the expectation value of the time-ordered product of fields over the vacuum. In some cases, especially in degenerate systems, expectation values over general states are required. The corresponding Green functions are essentially more complex than in the vacuum, because they cannot be written in terms of standard Feynman diagrams. Here, a method is proposed to determine the structure of these Green functions and to derive nonperturbative equations for them. The main idea is to transform the cumulants describing correlations into interaction terms.Comment: 13 pages, 6 figure

Photonic qubits, qutrits and ququads accurately prepared and delivered on demand

Reliable encoding of information in quantum systems is crucial to all approaches to quantum information processing or communication. This applies in particular to photons used in linear optics quantum computing (LOQC), which is scalable provided a deterministic single-photon emission and preparation is available. Here, we show that narrowband photons deterministically emitted from an atom-cavity system fulfill these requirements. Within their 500 ns coherence time, we demonstrate a subdivision into d time bins of various amplitudes and phases, which we use for encoding arbitrary qu-d-its. The latter is done deterministically with a fidelity >95% for qubits, verified using a newly developed time-resolved quantum-homodyne method.Comment: 5 pages, 4 figure

β-glycine piezoelectric and ferroelectric properties behavior at elevated temperatures

The research was carried out using equipment of Ural Center for Shared Use "Modern Nanotechnologies" Ural Federal University. The reported study was funded by RFBR according to the research project № 18-32-00390

Magnetic bound states in the quarter-filled ladder system α′−NaV2O5\alpha'-NaV_{2}O_{5}}

Raman scattering in the quarter-filled spin ladder system alpha'-NaV_2O_5 shows in the dimerized singlet ground state ($T \leq T_{SP}=35K$) an unexpected sequence of three magnetic bound states. Our results suggest that the recently proposed mapping onto an effective spin chain for $T > T_{SP}$ has to be given up in favor of the full topology and exchange paths of a ladder in the dimerized phase for $T < T_{SP}$. As the new ground state we propose a dynamic superposition of energetically nearly degenerate dimer configurations on the ladder.Comment: 5 pages, 4 figures, to be published in PRB, brief reports, Dec. 199

Synthesis and crystal structure of a new hexagonal perovskite 7H-Ba7Li1.75Mn3.5O15.75 with Mn4+/Mn5+ charge distribution.

Our work describes the synthesis and crystal structure of a new hexagonal perovskite 7H-Ba7Li1.75Mn3.5O15.75with Mn4+/Mn5+charge distribution.</p

Operator approach to analytical evaluation of Feynman diagrams

The operator approach to analytical evaluation of multi-loop Feynman diagrams is proposed. We show that the known analytical methods of evaluation of massless Feynman integrals, such as the integration by parts method and the method of "uniqueness" (which is based on the star-triangle relation), can be drastically simplified by using this operator approach. To demonstrate the advantages of the operator method of analytical evaluation of multi-loop Feynman diagrams, we calculate ladder diagrams for the massless $\phi^3$ theory (analytical results for these diagrams are expressed in terms of multiple polylogarithms). It is shown how operator formalism can be applied to calculation of certain massive Feynman diagrams and investigation of Lipatov integrable chain model.Comment: 16 pages. To appear in "Physics of Atomic Nuclei" (Proceedings of SYMPHYS-XII, Yerevan, Armenia, July 03-08, 2006

Molecular packing, piezo- and pyroelectric properties of tert-butyl N-(tert-butoxycarbonyl)-(S)-prolinamide

The work was financially supported by the Russian Foundation for Basic Research (grant no. 16-33-60122). The equipment of the Ural Centre for Shared Use “Modern Nanotechnologies” UrFU and Centre for Joint Use “Spectroscopy and Analysis of Organic Compounds” was used